A magnetic tape winding apparatus is known that can feed magnetic tape out of a supply reel having a long tape wound therein, and wind it on a cassette. The tape winding apparatus supplies a cassette from a cassette magazine into a cassette holder, and insert a winding shaft into a hub of the cassette. It pulls a leader tape out of the cassette, cuts the leader tape, and splices an end of the cut leader tape to the side of the winding shaft with an end of the magnetic tape fed out. It revolves the winding shaft and the supply reel to wind the magnetic tape into the cassette to a predetermined length, and stops the winding shaft and the supply reel. The apparatus then cuts the magnetic tape, and splices the remaining end of the cut leader tape to the other end of the magnetic tape on the side of the winding shaft. It then winds a little of the magnetic tape and the leader tape outside the cassette into the cassette with the winding shaft, and ejects the completed cassette.
The winding shaft has been known to have a pawl or similar projection on a circumference thereof so that it can fit in a groove in a center hole of the hub. The pawl is turnably held on a support provided in a groove on the winding shaft and is supported by a spring. The pawl, which is usually out of the winding shaft, can be concealed in the winding shaft by an external force exerted on the pawl. This facilitates easy insertion of the winding shaft in the hub.
As for construction and operation of the winding shaft, these have been disclosed, for example, in Japanese Utility Model Publicity S58-131469. In this prior art, the pawl is actuated from the center of the winding shaft by a cone rod. To insert the hub into or pull it out of the winding shaft, the pawl is pushed into the winding shaft. To revolve the winding shaft to wind the magnetic tape, the pawl projects out of the winding shaft to fit in the groove of the center hole of the hub. This prevents an insertion error that may occasionaly occur when the hub is inserted into the winding shaft.
However, the magnetic tape winding apparatus and method heretofore used have the disadvantage of scratching the leader tape when an audio magnetic tape and similar thin magnetic tapes are wound, or when the leader tape is pulled out of the cassette. This is due to the fact that with the pawl in the groove of the center hole of the hub when the leader tape is pulled out by an external force, the leader tape has the inertia force of the motor connected with the winding shaft exerted on it. This inertia force can cause the tape to rub against surfaces it is in contact with when the tape is quickly accelerated or decelerated.
In view of the foregoing, it is a general object of the present invention to provide a magnetic tape winding method and apparatus that is simple in operation and construction to pull a leader tape out of a cassette smoothly in a short time without scratching the tape.